Immunomodulation of Oxidative Stress during Organ Donation Process: Preliminary Results.

The objective was to quantify oxidative stress resulting from ischemia during the donation process, using malondialdehyde (MDA) measurement, and its modulation by the administration of melatonin. We designed a triple-blind clinical trial with donors randomized to melatonin or placebo. We collected donors by donation after brain death (DBD) and controlled donation after circulatory death (DCD), the latter maintained by normothermic regional perfusion (NRP). Melatonin or placebo was administered prior to donation or following limitation of therapeutic effort (LTE). Demographic variables and medical history were collected. We also collected serial measurements of MDA, at 60 and 90 min after melatonin or placebo administration. A total of 53 donors were included (32 from DBD and 21 from DCD). In the DBD group, 17 donors received melatonin, and 15 placebo. Eight DCD donors were randomized to melatonin and 13 to placebo. Medical history and cause for LTE were similar between groups. Although MDA values did not differ in the DBD group, statistical differences were observed in DCD donors during the 0-60 min interval: -4.296 (-6.752; -2.336) in the melatonin group and -1.612 (-2.886; -0.7445) in controls. Given the antioxidant effect of melatonin, its use could reduce the production of oxidative stress in controlled DCD.

Prolonged Mechanical Ventilation as a Predictor of Mortality After Cardiac Surgery.

BACKGROUND: Mortality among the small percentage of cardiac surgery patients receiving prolonged mechanical ventilation is high, but this issue appears to be inadequately addressed in guidelines. METHODS: This study is a retrospective analysis of prospective, multi-center, and observational study in Spain including all adults undergoing cardiac surgery in 3 Andalusian hospitals between June 2008 and December 2012. RESULTS: The study included 3,588 adults with mean ± SD age of 63.5 ± 12.8 y and with median (interquartile range) EuroSCORE of 5 (3-7) points. Prolonged mechanical ventilation (> 24 h) was required by 415 subjects (11.6%), with ICU mortality of 44.3% (184 subjects), and was not required by 3,173 subjects (88.4%), with ICU mortality of 3.1% (99 subjects, P < .001). Prolonged mechanical ventilation was associated with more complications and was required by 4.5% of subjects with a EuroSCORE <5, 11.2% with a score of 5-7, 27.2% with a score of 8-10, and 32.2% with a score > 10. In the multivariable analysis, ICU mortality was associated with illness severity, duration of bypass surgery, surgery type, and prolonged mechanical ventilation (odds ratio 15.19, 95% CI 11.56-22.09). The main cause of death was multiple organ failure and sepsis in subjects who required prolonged mechanical ventilation (50.3%) and cardiogenic shock in those who did not (59.2%). CONCLUSION: Prolonged postoperative mechanical ventilation was required by 10-20% of cardiac surgery subjects, who constitute a specific group that represents most of the postoperative mortality, which is associated with multiple organ failure and sepsis.